New research finds that caregivers need only “get it right” 50 percent of the time when responding to babies’ need for attachment to have a positive impact on a baby.

For the new study, Dr. Susan S. Woodhouse, an associate professor of counseling psychology at Lehigh University, studied 83 low socioeconomic-status mothers and infants at ages 4.5 months, 7 months, 9 months, and 12 months to assess attachment. Infants and mothers in the study were racially and ethnically diverse, and infants were selected for high levels of temperamental irritability, Woodhouse noted.

The researchers scored mother-baby pairs based on a mother’s responses to the infant while the baby was crying and not crying to assess the qualities of “secure base provision.” This framework focuses on aspects of caregiving that tell an infant about the caregiver’s availability to serve as a secure base, such as soothing crying and providing a safe base from which to explore.

Researchers found that this framework significantly predicted infant attachment. It also found that babies learned their mothers were providing a secure base when mothers responded properly at least 50 percent of the time.

“The findings provide evidence for the validity of a new way of conceptualizing the maternal caregiving quality that actually works for low-income families,” Woodhouse said.

Woodhouse noted infant attachment is the bond babies form with their primary caregiver. A secure attachment allows babies to feel safe, which gives them both comfort in times of distress and the ability to explore, knowing they can return to their secure base when needed. Attachment is an infant’s first bond with important caregivers and a critical phase in development, with a major impact on emotional and social development, she said.

Numerous studies have shown the importance of secure infant attachment to developmental outcomes. But the actual building blocks leading to attachment have been unresolved, according to Woodhouse.

Caregiver sensitivity — the ability to accurately interpret infant needs and to respond promptly and appropriately — was shown to be a key predictor of attachment. But previous studies showed sensitivity accounts for a surprisingly low percentage of variation in attachment, and has an even lower impact among families with low socioeconomic status, she said.

“That’s a real problem, because low-income babies face the most amount of risk, toxic stress, and other factors that go along with being low income,” Woodhouse explained.

Data suggest secure attachment may serve a protective function in children’s socio-emotional development when in a context of high risk. Secure attachment is associated with better mental health outcomes in both childhood and adulthood,including less incidence of externalizing behaviors such as acting out and internalizing behaviors such as depression and anxiety, as well as greater school readiness.

“If we want to give advice to parents about what they can do to give their baby the best start in life, it would be really good to know what helps a baby to be secure,” Woodhouse said.

The new study was designed to examine whether secure base provision — the degree to which a caregiver is able to meet an infant’s needs on both sides of the attachment-exploration continuum — predicts attachment security in infants.

Both sensitivity and secure base provision look at how caregivers perceive, interpret, and appropriately respond to infant signals, the researcher said. In both, important infant signals occur at each end of the attachment-exploration continuum.

But secure base provision looks only at certain key infant signals and more specific caregiver responses, Woodhouse said. It also focuses much less on prompt response and more on crying resolution, such as the ratio of infant crying episodes that end in chest-to-chest soothing until the infant is fully calmed, regardless of promptness.

Secure base provision does not consider attunement to a baby’s state and mood in a moment-by-moment manner, as the sensitivity framework does, she said.

“Attunement is not key because the focus is on what the infant learns about his or her ability to, in the end, recruit the caregiver when needed — even in the context of a fair degree of insensitive behavior,” such as not picking up the baby right away, or saying, “Come on, don’t cry,” to the baby, the researchers said. “It is this infant learning about the availability of the caregiver to be recruited to provide a secure base more often than not that is central to the construct.”

Specifically, secure base provision looks at the degree to which a parent, on average, soothes a crying infant to a fully calm and regulated state while in chest-to-chest contact.

“It is at the end of each crying episode that the infant learns about whether, on average, the caregiver can be counted on to be available as the infant achieves a calm state or whether the infant typically must stop crying alone,” the researchers said.

During infant exploration and other times when the infant is not distressed, the secure base provision approach focuses on whether the caregiver allows exploration to occur without terminating or interrupting it — for example, by making the baby cry through play that is too sudden or rough — and on “calm connectedness,” which communicates the mother’s ongoing availability if needed for regulation or protection, showing the baby the mother is there for them and that the baby can count on the mother.

During the study, researchers scored mother-baby pairs based on maternal responses to the infant during episodes of infant crying and maternal responses outside of infant crying episodes. A separate group in another lab also scored for the commonly used sensitivity framework.

The researchers found the new maternal caregiving concept of secure base provision correlated significantly with infant attachment security. Mothers who had higher scores on secure base provision were more likely to have more securely attached infants, with an effect eight times larger than that of sensitivity, according to the study’s findings.

This was true, even after controlling for maternal sensitivity. They also found that maternal sensitivity did not significantly predict infant attachment security.

“What this paper tells us is that we need to change not only how we measure sensitivity, but how we are thinking about the caregiving behaviors that really matter,” Woodhouse said. “What we found was that what really matters is not really so much that moment-to-moment matching between what the baby’s cue is and how the parent responds. What really matters is, in the end, does the parent get the job done — both when a baby needs to connect, and when a baby needs to explore?”

Research suggests that infants demonstrate statistical learning to identify complex underlying patterns in stimuli, according to the researchers.

“We expected that infants whom caregivers soothed from crying to calm in a chest-to-chest position for at least half of the observed episodes of infant crying would learn that, on average, they could trust their caregivers to provide a secure base,” the researchers said, noting that found that to be true.

Woodhouse calls the findings “paradigm shifting.”

“It really is a different way of looking at the quality of parenting,” she said. “It’s looking at this idea of does the job get done in the end, and it allows us to see strengths in low-income parents that our previous ideas about sensitivity don’t let us see.”

Researchers also noted a number of problematic behaviors by mothers while their babies were crying that disrupted the process of comforting the infant. These included turning the baby away from their chests before crying ends, rough handling, harsh verbal tones, verbal instructions not to cry, and verbally attributing negative characteristics to the baby. They also documented frightening behavior, such as sudden looming into the baby’s face or toward the baby, during crying episodes.

“If the mother did frightening things when the baby cried, like hard yelling or growling at the baby, or suddenly looming toward the baby’s face while the baby was upset, even if it only happened one time, the baby would be insecure,” Woodhouse said.

“Similarly, if the mother did anything really frightening even when the baby wasn’t in distress, like saying ‘bye-bye’ and pretending to leave, throwing the baby in the air to the point they would cry, failure to protect the baby, like walking away from the changing table or not protecting them from an aggressive sibling, or even what we call ‘relentless play’ — insisting on play and getting the baby worked up when it is too much — that also leads to insecurity.”

On the flip side, overprotective behaviors, such as moms who don’t let the baby explore more than an arm’s length away, or interrupting or redirecting play (except for safety) also contributed to insecure baby attachment.

“Some moms really had trouble allowing the baby to explore and were very insistent on the baby doing certain things or turning the baby’s head to look at the mom,” Woodhouse said. “In really intrusive parenting, if we saw that, the baby was insecure.”

Woodhouse notes there are several takeaways from the study for parents.

“The first message gets at the core of getting the job done — supporting the baby in exploration and not interrupting it and welcoming babies in when they need us for comfort or protection,” she said. “The other part is that you don’t have to do it 100 percent. You have to get it right about half of the time, and babies are very forgiving and it’s never too late.”